Worse stroke outcome in atrial fibrillation is explained by more severe hypoperfusion, infarct growth, and hemorrhagic transformation

Thromboembolic events and vascular dementia in patients with atrial fibrillation and low apparent stroke risk

The prevention of thromboembolism in atrial fibrillation (AF) is typically restricted to patients with specific risk factors and ignores outcomes such as vascular dementia. This population-based cohort study used electronic healthcare records from 5,199,994 primary care patients (UK; 2005-2020). A total of 290,525 (5.6%) had a diagnosis of AF and were aged 40-75 years, of which 36,340 had no history of stroke, a low perceived risk of stroke based on clinical risk factors and no oral anticoagulant prescription. Matching was performed for age, sex and region to 117,298 controls without AF. During 5 years median follow-up (831,005 person-years), incident stroke occurred in 3.8% with AF versus 1.5% control (adjusted hazard ratio (HR) 2.06, 95% confidence interval (CI) 1.91-2.21; P < 0.001), arterial thromboembolism 0.3% versus 0.1% (HR 2.39, 95% CI 1.83-3.11; P < 0.001), and all-cause mortality 8.9% versus 5.0% (HR 1.44, 95% CI 1.38-1.50; P < 0.001). AF was associated with all-cause dementia (HR 1.17, 95% CI 1.04-1.32; P = 0.010), driven by vascular dementia (HR 1.68, 95% CI 1.33-2.12; P < 0.001) rather than Alzheimer's disease (HR 0.85, 95% CI 0.70-1.03; P = 0.09). Death and thromboembolic outcomes, including vascular dementia, are substantially increased in patients with AF despite a lack of conventional stroke risk factors.

Etiological Subclassification of Stroke in Older People ≥80 Years Compared to Younger People: A Systematic Review and Meta-Analysis

BACKGROUND

Due to the rapid growth of the world´s oldest population, the number of older persons with stroke is expected to rise. Knowledge of stroke etiology is essential to offer personalized and equal health care across age groups. The present systematic review aimed to investigate the prevalence of etiological subtypes of ischemic and hemorrhagic stroke in older compared to younger people.

METHODS

MEDLINE, Embase, Cochrane, Epistemonikos, and Cinahl were systematically searched for studies regarding etiological classification in people ≥80 years compared to those <80 years with ischemic or hemorrhagic stroke.

RESULTS

Out of 28 441 identified articles, eight met the inclusion criteria. In total, 8223 individuals were included in meta-analyses, of whom 2997 were 80 years or older. We demonstrated a higher prevalence of cardioembolic stroke in people ≥80 years OR 1.68 (95% CI, 1.12-2.53). Small vessel disease was significantly less common in older people OR .64 (95% CI, .50-.81). Regarding large vessel disease, no statistically significant difference between the two groups was shown OR 1.05 (95% CI, .77-1.43).

CONCLUSION

In people ≥80 years, cardioembolic stroke is more common, and small vessel disease less common compared to people <80 years. Overall, the results have to be interpreted with caution due to few studies. Large studies using validated classification systems are needed.

An Explainable Artificial Intelligence Model to Predict Malignant Cerebral Edema after Acute Anterior Circulating Large-Hemisphere Infarction

INTRODUCTION

Malignant cerebral edema (MCE) is a serious complication and the main cause of poor prognosis in patients with large-hemisphere infarction (LHI). Therefore, the rapid and accurate identification of potential patients with MCE is essential for timely therapy. This study utilized an artificial intelligence-based machine learning approach to establish an interpretable model for predicting MCE in patients with LHI.

METHODS

This study included 314 patients with LHI not undergoing recanalization therapy. The patients were divided into MCE and non-MCE groups, and the eXtreme Gradient Boosting (XGBoost) model was developed. A confusion matrix was used to measure the prediction performance of the XGBoost model. We also utilized the SHapley Additive exPlanations (SHAP) method to explain the XGBoost model. Decision curve and receiver operating characteristic curve analyses were performed to evaluate the net benefits of the model.

RESULTS

MCE was observed in 121 (38.5%) of the 314 patients with LHI. The model showed excellent predictive performance, with an area under the curve of 0.916. The SHAP method revealed the top 10 predictive variables of the MCE such as ASPECTS score, NIHSS score, CS score, APACHE II score, HbA1c, AF, NLR, PLT, GCS, and age based on their importance ranking.

CONCLUSION

An interpretable predictive model can increase transparency and help doctors accurately predict the occurrence of MCE in LHI patients not undergoing recanalization therapy within 48 h of onset, providing patients with better treatment strategies and enabling optimal resource allocation.

Blood pressure variability and outcome in atherosclerosis versus cardioembolism cerebral large vessel occlusion after successful thrombectomy

Higher blood pressure variability (BPV) has been proven associated with worse functional outcome after endovascular treatment (EVT). However, this association is not established according to different stroke etiologies. In this study, we compared patients with the two highest proportions of stroke etiologies-cardioembolism (CE) and large-artery atherosclerosis (LAA), aiming to explore appropriate strategies of BP management for different etiologies. We enrolled patients with large vessel occlusion (LVO) in anterior circulation who underwent EVT and achieved successful recanalization retrospectively. 24-h blood pressure (BP) and BPV measured as blood pressure reduction (BPr), standard deviation (SD), coefficient of variation (CV), successive variation (SV), average real variability (ARV) after EVT were collected for systolic blood pressure (SBP) and diastolic blood pressure (DBP). The favorable outcome was defined as functional independence by 90-day modified Rankin Scale (mRS 0-2). In our cohort, higher BPV parameters significantly resulted in 90d functional dependence in CE-LVO patients (SBPSV OR: 1.083, 95%CI = 1.009-1.163; SBPARV OR: 1.121, 95%CI = 1.019-1.233; DBPSD OR: 1.124, 95%CI = 1.007-1.1256; DBPCV OR: 1.078, 95%CI = 1.002-1.161). However, for LAA-LVO patients, no positive results correlated 90d functional dependence with 24-hour BPV. Additionally, 90d functional dependence in CE patients with poor collaterals were significantly dependent on post-procedural BPV (DBPmax OR: 1.044, 95%CI = 1.002-1.087; DBPSD OR: 1.229, 95%CI = 1.022-1.1.479; DBPCV OR: 1.143, 95%CI = 1.009-1.295). Whereas to patients with good collaterals, there did not exist such a correlation. In summary, stroke etiologies should probably be taken into consideration to optimize individualized BP management strategies. In order to achieve better clinical outcomes for patients with acute ischemic stroke due to large vessel occlusion, stricter blood pressure management should be taken in cardioembolic stroke patients in contrast with large artery atherosclerotic stroke patients after successful endovascular therapy.

The impact of blood pressure variability on the development of parenchymal hematoma in acute cerebral infarction with atrial fibrillation

Although blood pressure variability (BPV) and reperfusion are associated with parenchymal hematoma (PH) after stroke, the relationship between BPV and PH in atrial fibrillation (AF) patients who are at risk of reperfusion injury with frequent spontaneous recanalization is unknown. This study aimed to investigate whether BPV within the first 48 h is associated with PH within 72 h in patients with AF and stroke in terms of major vessel occlusion status. A total of 131 patients with AF that were admitted within 24 h after stroke onset were enrolled. PH was defined as a confluent hemorrhage with mass effect. The maximum (max), minimum (min), and average blood pressure (BP) during the first 48 h after admission were calculated. BPV was analyzed by using range between maximum and minimum (max-min), successive variation (SV), standard deviation (SD), and coefficient of variation (CV). All parameters were applied for systemic (SBP), diastolic (DBP), and pulse pressure (PP). After adjusting for confounding variables, various BPV parameters were associated with PH, including SBPmax (p = 0.0426), SBPSV (p = 0.0006), DBPmax-min (p = 0.0437), DBPSV (p = 0.0358), DBPSD (p = 0.0393), PPmax-min (p = 0.0478), PPSV (p < 0.0001), PPSD (p = 0.0034), and PPCV (p = 0.0120). The relationship remained significant in patients with a patent major vessel responsible for infarction but not in patients with an occluded major vessel. In conclusion, this study revealed that high BPV was associated with PH in patients with AF and acute stroke, particularly for those with a patent major vessel. The control of BP and BPV after stroke may be considered in patients with AF.

Association of Atrial Fibrillation with Remote Intracerebral Hemorrhage After Intravenous Thrombolysis: Results from a Multicenter Study in China

INTRODUCTION

This study aimed to investigate the association between atrial fibrillation (AF), particularly newly diagnosed AF, and remote intracerebral hemorrhage (rICH) in patients with ischemic stroke who were treated with intravenous thrombolysis (IVT).

METHODS

This observational study was conducted on patients with ischemic stroke who received IVT with recombinant tissue-type plasminogen activator. The data were taken from a multicenter prospective registry of a Chinese population. rICH was defined as any extraischemic hemorrhage detected on computerized tomography (CT) 24 h after intravenous thrombolysis. We collected and compared the demographic data and clinical characteristics of all the patients with rICH to those of patients without any type of hemorrhagic transformation. The association between AF and rICH was analyzed using univariate analysis and binary logistic regression.

RESULTS

A total of 20,697 patients were included in the study, with 1566 (7.6%) experiencing intracerebral hemorrhage (ICH), 586 (2.8%) experiencing rICH, and 19,131 (92.4%) not experiencing any form of hemorrhagic transformation. Univariate analysis revealed significant differences in age, pre-thrombolysis systolic blood pressure, baseline National Institute of Health Stroke Scale score, previously known AF, newly diagnosed AF, coronary heart disease, congestive heart failure, hyperhomocysteinemia, and history of thrombolysis between the rICH and control groups (P < 0.05). Further multivariate logistic regression analysis indicated that total AF (OR 1.821, 95% CI 1.082-3.065, P < 0.05), previously known AF (OR 1.470, 95% CI 1.170-1.847), and newly diagnosed AF (OR 1.920, 95% CI 1.304-2.825) were independently associated with rICH.

CONCLUSIONS

This study suggests that AF, regardless of whether it is newly diagnosed or previously known, may be associated with the occurrence of rICH following intravenous thrombolysis. Interestingly, our findings suggest that newly diagnosed AF may have a stronger impact on rICH than previously known AF, although confirmation from more studies is needed.

Early neurological deterioration in patients with minor stroke due to isolated M2 occlusion undergoing medical management: a retrospective multicenter study

BACKGROUND

Patients with minor stroke and M2 occlusion undergoing best medical management (BMM) may face early neurological deterioration (END) that can lead to poor long-term outcome. In case of END, rescue mechanical thrombectomy (rMT) seems beneficial. Our study aimed to define factors relevant to clinical outcome in patients undergoing BMM with the possibility of rMT on END, and find predictors of END.

METHODS

Patients with M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score≤5 that received either BMM only or rMT on END after BMM were extracted from the databases of 16 comprehensive stroke centers. Clinical outcome measures were a 90-day modified Rankin Scale (mRS) score of 0-1 or 0-2, and occurrence of END.

RESULTS

Among 10 169 consecutive patients with large vessel occlusion admitted between 2016 and 2021, 208 patients were available for analysis. END was reported in 87 patients that were therefore all subjected to rMT. In a logistic regression model, END (OR 3.386, 95% CI 1.428 to 8.032), baseline NIHSS score (OR 1.362, 95% CI 1.004 to 1.848) and a pre-event mRS score=1 (OR 3.226, 95% CI 1.229 to 8.465) were associated with unfavorable outcome. In patients with END, successful rMT was associated with favorable outcome (OR 4.549, 95% CI 1.098 to 18.851). Among baseline clinical and neuroradiological features, presence of atrial fibrillation was a predictor of END (OR 3.547, 95% CI 1.014 to 12.406).

CONCLUSION

Patients with minor stroke due to M2 occlusion and atrial fibrillation should be closely monitored for possible worsening during BMM and, in this case, promptly considered for rMT.

The mediating role of atrial fibrillation in causal associations between risk factors and stroke: a Mendelian randomization study

OBJECTIVES

Atrial fibrillation (AF) contributes to stroke development and progression. We aimed to quantify the mediating role of AF in the causal associations between a wide range of risk factors and stroke via a Mendelian randomization (MR) framework.

METHODS

We assessed the associations of 108 traits with stroke and its subtypes in a 2-sample univariable MR approach, then conducted a bidirectional MR analysis between these 108 traits and AF to evaluate the presence and direction of their causal associations. Finally, to further investigate the extent to which AF mediated the effects of eligible traits on stroke, we applied multivariable and 2-step MR techniques in a mediation analysis where outcomes were restricted to stroke types causally affected by AF (any stroke [AS], any ischemic stroke [AIS], and cardioembolic stroke [CES]).

RESULTS

Among 108 traits, 42 were putatively causal for at least 1 stroke type; of these 42 traits, 20 that had no bidirectional relationship with AF were retained. Finally, 33 associations of 15 eligible traits were examined in the mediation analysis. The mediation analyses for AS, AIS, and CES each included 11 eligible traits. After AF adjustment, the direct effects of all traits on CES were attenuated to null (all p>0.05), while the associations with AS and AIS persisted for most traits (AF-mediated proportion: from 6.6% [95% confidence interval, 2.7 to 0.6] to 52.0% [95% confidence interval, 39.8 to 64.3]).

CONCLUSIONS

The causal associations between all eligible traits and CES were largely mediated through AF, while most traits affected AS and AIS independently of AF.

Hypercoagulability on Thromboelastography Can Predict the Functional Outcomes in Patients with Acute Ischemic Stroke

BACKGROUND

 We investigated the association between the reaction time (R), a thromboelastography (TEG) parameter for hypercoagulability, and functional outcomes based on the occurrence of hemorrhagic transformation (HT) and early neurological deterioration (END).

METHODS

 We enrolled ischemic stroke patients and performed TEG immediately after the patients' arrival. The baseline characteristics, occurrence of HT and END, stroke severity, and etiology were compared according to the R. END was defined as an increase of ≥1 point in motor or ≥2 points in the total National Institute of Health Stroke Scale within 3 days after admission. The outcome was the achievement of functional independence (modified Rankin scale [mRS]: 0-2) at 3 months after stroke. Logistic regression analyses were performed to verify the association between R and outcome.

RESULTS

 HT and END were frequently observed in patients with an R of <5 minutes compared with the group with an R of ≥5 minutes (15 [8.1%] vs. 56 [21.0%], p < 0.001; 16 [8.6%] vs. 65 [24.3%], p = 0.001, respectively). In multivariable analysis, an R of <5 minutes was associated with decreased odds of achieving functional independence (0.58 [0.34-0.97], p = 0.038). This association was maintained when the outcome was changed to disability free (mRS 0-1) and when mRS was analyzed as an ordinal variable.

CONCLUSION

 Hypercoagulability on TEG (R <5 minutes) may be a negative predictor for functional outcome of stroke after 3 months, with more frequent HT, END, and different stroke etiologies. This study highlights the potential of TEG parameters as biomarkers for predicting functional outcomes in ischemic stroke patients.

Key CT markers for predicting haemorrhagic transformation after ischaemic stroke: a prospective cohort study in China

OBJECTIVES

Limited studies have systematically addressed the CT markers of predicting haemorrhagic transformation (HT). We aimed to (1) investigate the predictive ability of the imaging factors on multimodal CT for HT and (2) identify the key CT markers that can accurately predict HT while maintaining easy and rapid assessment in the early stage of stroke.

DESIGN AND SETTING

This was a prospective cohort study conducted in a tertiary hospital in Southwest China.

PARTICIPANTS

Patients with ischaemic stroke admitted within 24 hours after onset were included.

OUTCOME MEASURES

The primary outcome was measured as the overall HT. The secondary outcomes were the presence of parenchymal haematoma, symptomatic HT and spontaneous HT.

RESULTS

A total of 763 patients were included. The early hypodensity >1/3 of the middle cerebral artery (MCA) territory, Alberta Stroke Programme Early CT Score≤7, midline shift, hyperdense middle cerebral artery sign (HMCAS), poor collateral circulation, infarct core and penumbra was independently associated with the increased risk of HT (all p < 0.05). The sensitivity of midline shift for predicting HT was only 3.5%, whereas its specificity was 99.8%. The combination of the early hypodensity >1/3 of the MCA territory, midline shift and HMCAS showed a good predictive performance for HT (area under the curve 0.80, 95% CI 0.75 to 0.84).

CONCLUSIONS

Seven imaging factors on multimodal CT were independently associated with HT. The high specificity of midline shift suggests the need to consider it as an imaging indicator when assessing the risk of HT. The early hypodensity >1/3 of the MCA territory, midline shift and HMCAS was identified as the key CT markers for the early prediction of HT. The coexistence of the three key factors might be a valuable index for identifying individuals at high bleeding risk and guiding further treatments.

Modelling anticoagulation and health-related quality of life in those with atrial fibrillation: a secondary analysis of AFFIRM

Associations of anticoagulation with primary endpoints in longitudinal studies are impacted by selection bias and time-varying covariates (e.g. comorbidities). We demonstrate how time-varying covariates and selection bias influence association estimates between anticoagulation and health-related quality of life (HRQoL) in patients with atrial fibrillation. We performed a secondary analysis of the Atrial Fibrillation Follow-up Investigation of Rhythm Management trial quality of life substudy. Dichotomized warfarin use was ascertained at the study baseline, 2 months later, and annually for up to 6 years. HRQoL was measured at every time point using a self-reported ordinal 5-point Likert-scale (lower score and lower odds ratio represents better health-related quality of life). Static and time-varying covariates were ascertained throughout the study period. Confounder-adjusted generalized mixed model and generalized estimating equation regressions were used to demonstrate traditional association estimates between anticoagulation and HRQoL. Inverse probability of treatment and censorship weights were used to ascertain the influence of time-varying confounding and selection bias. Age-stratified analysis (age ≥ 70 years) evaluated for effect modification. 656 individuals were included in the analysis, 601 on warfarin at baseline. The association of warfarin use with better HRQoL over time strengthened when accounting for time-varying confounding and selection bias (OR 0.30, 95% CI 0.14-0.55) compared to traditional analyses (OR 0.61, 95% CI 0.38-0.97), and was most pronounced in those ≥ 70 years upon stratified analysis. Anticoagulation is associated with higher HRQoL in patients with atrial fibrillation, with time-varying confounding and selection bias likely influencing longitudinal estimates in anticoagulation-HRQoL research.

Diagnosis and Management of Atrial Fibrillation in Acute Ischemic Stroke in the Setting of Reperfusion Therapy: Insights and Strategies for Optimized Care

Reperfusion therapy in the form of intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) has revolutionised the field of stroke medicine. Atrial fibrillation (AF) patients constitute a major portion of the overall stroke population; however, the prevalence of AF amongst acute ischemic stroke (AIS) patients receiving reperfusion therapy remains unclear. Limitations in our understanding of prevalence in this group of patients are exacerbated by difficulties in appropriately diagnosing AF. Additionally, the benefits of reperfusion therapy are not consistent across all subgroups of AIS patients. More specifically, AIS patients with AF often tend to have poor prognoses despite treatment relative to those without AF. This article aims to present an overview of the diagnostic and therapeutic management of AF and how it mediates outcomes following stroke, most specifically in AIS patients treated with reperfusion therapy. We provide unique insights into AF prevalence and outcomes that could allow healthcare professionals to optimise the treatment and prognosis for AIS patients with AF. Specific indications on acute neurovascular management and secondary stroke prevention in AIS patients with AF are also discussed.

End-to-end risk prediction of atrial fibrillation from the 12-Lead ECG by deep neural networks

BACKGROUND

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias that affects millions of people each year worldwide and it is closely linked to increased risk of cardiovas- cular diseases such as stroke and heart failure. Machine learning methods have shown promising results in evaluating the risk of developing atrial fibrillation from the electrocardiogram. We aim to develop and evaluate one such algorithm on a large CODE dataset collected in Brazil.

METHODS

We used the CODE cohort to develop and test a model for AF risk prediction for individual patients from the raw ECG recordings without the use of additional digital biomarkers. The cohort is a collection of ECG recordings and annotations by the Telehealth Network of Minas Gerais, in Brazil. A convolutional neural network based on a residual network architecture was implemented to produce class probabilities for the classification of AF. The probabilities were used to develop a Cox proportional hazards model and a Kaplan-Meier model to carry out survival analysis. Hence, our model is able to perform risk prediction for the development of AF in patients without the condition.

RESULTS

The deep neural network model identified patients without indication of AF in the presented ECG but who will develop AF in the future with an AUC score of 0.845. From our survival model, we obtain that patients in the high-risk group (i.e. with the probability of a future AF case being >0.7) are 50% more likely to develop AF within 40 weeks, while patients belonging to the minimal-risk group (i.e. with the probability of a future AF case being less than or equal to 0.1) have >85% chance of remaining AF free up until after seven years.

CONCLUSION

We developed and validated a model for AF risk prediction. If applied in clinical practice, the model possesses the potential of providing valuable and useful information in decision- making and patient management processes.

Association between left atrial enlargement and poor cerebral collaterals in large vessel occlusion

OBJECTIVES

Left atrial enlargement (LAE) is a known risk factor for atrial fibrillation, a common cause of large vessel occlusion (LVO) leading to ischemic stroke. While robust cerebral collaterals protect penumbral tissue from infarction, the effect of structural heart disease on cerebral collaterals remains uncertain. This study aims to investigate the association between LAE and cerebral collaterals in patients with acute LVO stroke.

MATERIALS AND METHODS

We conducted a retrospective study of consecutive patients with middle cerebral and/or internal carotid LVO who underwent endovascular thrombectomy (EVT) between 2012 to 2020. Consecutive patients with echocardiography and computed tomography angiography (CTA) of the head were included. Multivariate logistic regression analysis was performed to evaluate the relationship between LAE and poor cerebral collaterals, adjusting for demographics (age, sex, race) and vascular risk factors (hypertension, diabetes and smoking).

RESULTS

The study included 235 patients with mean age of 69±15 years and an initial mean National Institutes of Health Stroke Scale score of 18. Of these, 89 (37.9 %) had LAE, and 105 (44.7 %) had poor collaterals. Patients with LAE were more likely to have poor collaterals compared to those without LAE (58.4 % vs 36.3 %, P = 0.001). LAE was independently associated with higher odds of poor collaterals (odds ratio, 2.47; P = 0.001), even after adjusting for covariables (odds ratio 1.84, P = 0.048).

CONCLUSIONS

Our study demonstrated a significant association between LAE and poor cerebral collaterals in patients with LVO stroke undergoing EVT. Further research is warranted to explore potential shared mechanisms, such as endothelial dysfunction, underlying this heart-brain association.

Development and validation of a nomogram for the risk prediction of malignant cerebral edema after acute large hemispheric infarction involving the anterior circulation

Background

Malignant cerebral edema (MCE) is a life-threatening complication of large hemisphere infarction (LHI). Therefore, a fast, accurate, and convenient tool for predicting MCE can guide triage services and facilitate shared decision-making. In this study, we aimed to develop and validate a nomogram for the early prediction of MCE risk in acute LHI involving the anterior circulation and to understand the potential mechanism of MCE.

Methods

This retrospective study included 312 consecutive patients with LHI from 1 January 2019 to 28 February 2023. The patients were divided into MCE and non-MCE groups. MCE was defined as an obvious mass effect with ≥5 mm midline shift or basal cistern effacement. Least absolute shrinkage and selection operator (LASSO) and logistic regression were performed to explore the MCE-associated factors, including medical records, laboratory data, computed tomography (CT) scans, and independent clinic risk factors. The independent factors were further incorporated to construct a nomogram for MCE prediction.

Results

Among the 312 patients with LHI, 120 developed MCE. The following eight factors were independently associated with MCE: Glasgow Coma Scale score (p = 0.007), baseline National Institutes of Health Stroke Scale score (p = 0.006), Alberta Stroke Program Early CT Score (p < 0.001), admission monocyte count (p = 0.004), white blood cell count (p = 0.002), HbA1c level (p < 0.001), history of hypertension (p = 0.027), and history of atrial fibrillation (p = 0.114). These characteristics were further used to establish a nomogram for predicting prognosis. The nomogram achieved an AUC-ROC of 0.89 (95% CI, 0.82-0.96).

Conclusion

Our nomogram based on LASSO-logistic regression is accurate and useful for the early prediction of MCE after LHI. This model can serve as a precise and practical tool for clinical decision-making in patients with LHI who may require aggressive therapeutic approaches.

Impact of prior use of antiplatelet agents and non-vitamin K antagonist oral anticoagulants on stroke outcomes among endovascular-treated patients with high pre-stroke CHA2DS2-VASc score

BACKGROUND

We assessed the influence of prior non-vitamin K antagonist (NOAC) use on stroke outcomes after endovascular treatment (EVT) in patients at a high risk of stroke based on their pre-stroke CHA2DS2-VASc score, and compared them with those who did not use any antithrombotic (NAU) or antiplatelet (APT) agents.

METHODS

Data were collected from a multicenter database comprising consecutive acute ischemic stroke patients who underwent EVT during a span of 103 months. We evaluated pre-stroke CHA2DS2-VASc scores in enrolled patients and measured instances of successful reperfusion and symptomatic hemorrhagic transformation (SHT) following EVT as the main outcome measures.

RESULTS

Among 12 807 patients with acute ischemic stroke, 3765 (29.4%) had a history of atrial fibrillation. Of these, 418 patients with CHA2DS2-VASc scores ≥2 received EVT alone. The prior NOAC group showed higher successful reperfusion rates compared with the prior NAU and APT groups (p=0.04). Multivariate analysis revealed that prior NOAC use increased the likelihood of successful reperfusion after EVT (OR [95% CI] 2.54 [1.34 to 4.83], p=0.004) and improved stroke outcomes, while the prior APT group did not. Furthermore, the prior NOAC use group was not associated with SHT after EVT. Propensity score matching confirmed these findings.

CONCLUSION

Prior use of NOAC is associated with improved outcomes in high-risk stroke patients (pre-stroke CHA2DS2-VASc score ≥2) undergoing EVT.

Tmax volume can predict clinical type in patients with acute ischemic stroke

OBJECTIVE

Endovascular therapy (EVT) is performed for acute ischemic stroke (AIS) with large vessel occlusion (LVO), however, the treatment strategies and clinical outcomes differ between cardiac embolism (CE) and intracranial arteriosclerosis-derived LVO (ICAS-LVO). We analyzed whether the time-to-max (Tmax) volume derived from perfusion imaging predicted clinical classification in AIS patients before EVT.

METHODS

Consecutive AIS patients with anterior circulation LVO evaluated by automated imaging software were retrospectively identified. Patients were classified into a CE group and an ICAS-LVO group, and parameters were compared between groups.

RESULTS

Thirty-nine patients were included and Tmax volume and Tmax > 6 s volume/Tmax > 4 s volume were significantly greater in the CE group than in the ICAS-LVO group (Tmax > 4 s volume: 261 mL vs. 149 mL, p = .01, Tmax > 6 s volume: 143 mL vs. 59 mL, p = .001, Tmax > 6 s volume/Tmax > 4 s volume: 0.59 vs. 0.40, p < .001). Multiple logistic regression analysis indicated an association between clinical classification and high Tmax > 6 s volume/Tmax > 4 s volume (p = .04).

CONCLUSION

The Tmax volume derived from perfusion imaging predicts the clinical classification of AIS patients before EVT.

Association between Rapid Ventricular Response and Stroke Outcomes in Atrial Fibrillation-Related Cardiac Embolic Stroke

INTRODUCTION

Patients with atrial fibrillation-related stroke (AF-stroke) are prone to developing rapid ventricular response (RVR). We investigated whether RVR is associated with initial stroke severity, early neurological deterioration (END) and poor outcome at 3 months.

METHODS

We reviewed patients who had AF-stroke between January 2017 and March 2022. RVR was defined as having heart rate >100 beats per minute on initial electrocardiogram. Neurological deficit was evaluated with National Institutes of Health Stroke Scale (NIHSS) score at admission. END was defined as increase of ≥2 in total NIHSS score or ≥1 in motor NIHSS score within first 72 h. Functional outcome was score on modified Rankin Scale at 3 months. Mediation analysis was performed to examine potential causal chain in which initial stroke severity may mediate relationship between RVR and functional outcome.

RESULTS

We studied 568 AF-stroke patients, among whom 86 (15.1%) had RVR. Patients with RVR had higher initial NIHSS score (p < 0.001) and poor outcome at 3 months (p = 0.004) than those without RVR. The presence of RVR [adjusted odds ratio (aOR) = 2.13; p = 0.013] was associated with initial stroke severity, but not with END and functional outcome. Otherwise, initial stroke severity [aOR = 1.27; p = <0.001] was significantly associated with functional outcome. Initial stroke severity as a mediator explained 58% of relationship between RVR and poor outcome at 3 months.

CONCLUSION

In patients with AF-stroke, RVR was independently associated with initial stroke severity but not with END and functional outcome. Initial stroke severity mediated considerable proportion of association between RVR and functional outcome.

Poor collateral flow with severe hypoperfusion explains worse outcome in acute stroke patients with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is associated with poorer functional outcomes in acute stroke patients. It has been hypothesized that this is due to poor collateral recruitment.

AIMS

This study aimed to investigate the relationship between AF and collaterals with outcome in thrombectomy patients.

METHODS

This retrospective cohort study identified 1036 acute ischemic patients from the INternational Stroke Perfusion Imaging REgistry. The cohort was divided into two groups: 432 with AF and 604 without AF. Patients were stratified by collateral grades as good, moderate, and poor. Within each collateral grade, the prediction of AF versus No AF for good outcome (3-month modified Rankin Scale of 0-2) was determined. Then, within each collateral grade, perfusion was compared between those with and without AF.

RESULTS

AF was negatively associated with good outcome in patients with poor collaterals (26.7% vs 51.2% for AF vs No AF, odds ratio = 0.32 (95% confidence interval = 0.22-0.50), p < 0.001), but not in patients with good (50.9% vs 58.1% for AF vs No AF, odds ratio = 0.75 (0.46-1.23), p = 0.249) or moderate collaterals (43.6% vs 50.9% for AF vs No AF, odds ratio = 0.75 (0.47-1.18), p = 0.214). AF was associated with severe hypoperfusion only in patients with poor collateral flow (54.0 vs 35.5 mL for AF vs No AF, p < 0.001).

CONCLUSIONS

AF-related stroke is associated with more severe hypoperfusion and worse outcome in those with poor collaterals.

Imaging diagnosis of intracranial atherosclerosis stenosis-related large vessel occlusion before and during endovascular therapy

It is becoming increasingly important to identify the type of stroke, especially the mechanism of occlusion, before and during its treatment. In the case of intracranial atherosclerotic stenosis-related large vessel occlusion, it is necessary to develop a treatment strategy that includes not only mechanical thrombectomy but also adjunctive therapies such as primary or rescue therapy (percutaneous angioplasty, intracranial/carotid stenting, local fibrinolysis) and perioperative antithrombotic therapy. However, in clinical practice we often encounter cases where it is difficult to identify the occlusive mechanism before endovascular treatment because of insufficient information in the minimal circumstances of the hyperacute phase of stroke. Here we focus on the imaging diagnosis before and during treatment of intracranial atherosclerotic stenosis-related large vessel occlusion with in situ thrombotic occlusion as the mechanism of thrombotic occlusion, based on previous reports. We describe the diagnosis of intracranial atherosclerotic stenosis-related large vessel occlusion from the perspectives of "thrombus imaging," "perfusion," and "occlusion margin."

Early Hemorrhagic Transformation after Reperfusion Therapy in Patients with Acute Ischemic Stroke: Analysis of Risk Factors and Predictors

Background: The standard reperfusion therapy for acute ischemic stroke (AIS) is considered to be thrombolysis, but its application is limited by the high risk of hemorrhagic transformation (HT). This study aimed to analyze risk factors and predictors of early HT after reperfusion therapy (intravenous thrombolysis or mechanical thrombectomy). Material and methods: Patients with acute ischemic stroke who developed HT in the first 24 h after receiving rtPA thrombolysis or performing mechanical thrombectomy were retrospectively reviewed. They were divided into two groups, respectively, the early-HT group and the without-early-HT group based on cranial computed tomography performed at 24 h, regardless of the type of hemorrhagic transformation. Results: A total of 211 consecutive patients were enrolled in this study. Among these patients, 20.37% (n = 43; age: median 70.00 years; 51.2% males) had early HT. Multivariate analysis of independent risk factors associated with early HT found that male gender increased the risk by 2.7-fold, the presence of baseline high blood pressure by 2.4-fold, and high glycemic values by 1.2-fold. Higher values of NIHSS at 24 h increased the risk of hemorrhagic transformation by 1.18-fold, while higher values of ASPECTS at 24 h decreased the risk of hemorrhagic transformation by 0.6-fold. Conclusions: In our study, male gender, baseline high blood pressure, and high glycemic values, along with higher values of NIHSS were associated with the increased risk of early HT. Furthermore, the identification of early-HT predictors is critical in patients with AIS for the clinical outcome after reperfusion therapy. Predictive models to be used in the future to select more careful patients with a low risk of early HT need to be developed in order to minimize the impact of HT associated with reperfusion techniques.

Post-thrombolysis early neurological deterioration occurs with or without hemorrhagic transformation in acute cerebral infarction: risk factors, prediction model and prognosis

Objectives

Early neurological deterioration (END) after ischemic stroke is a severe clinical event and can be caused by hemorrhagic and ischemic injury. We studied the difference between the risk factors of END occurs with or without hemorrhagic transformation after intravenous thrombolysis.

Materials and methods

Consecutive cerebral infarction patients who underwent intravenous thrombolysis from 2017 to 2020 in our hospital were retrospectively recruited. END was defined as a ≥2 points increase on 24-h National Institutes of Health Stroke Scale (NIHSS) score after therapy compared with the best neurological status after thrombolysis and divided into two types based on the computed tomography (CT): symptomatic intracranial hemorrhage (ENDh) and non-hemorrhagic factors (ENDn). Potential risk factors of ENDh and ENDn were assessed by multiple logistic regression and applied to establish the prediction model.

Results

A total of 195 patients were included. In multivariate analysis, the previous history of cerebral infarction (odds ratio [OR],15.19; 95% confidence interval [CI],1.43-161.17; P = 0.025), previous history of atrial fibrillation (OR,8.43; 95%CI,1.09-65.44; P = 0.043), higher baseline NIHSS score (OR,1.19; 95%CI,1.03-1.39; P = 0.022) and higher alanine transferase level (OR,1.05; 95%CI, 1.01-1.10; P = 0.016) were independently associated with ENDh. While higher systolic blood pressure (OR,1.03; 95%CI,1.01-1.05; P = 0.004), higher baseline NIHSS score (OR,1.13; 95%CI,2.86-27.43; P < 0.000) and large artery occlusion (OR,8.85, 95%CI,2.86-27.43; P < 0.000) were independent risk factors of ENDn. The prediction model showed good specificity and sensitivity in predicting the risk of ENDn.

Conclusions

There are differences between the major contributors to ENDh and ENDn, while a severe stroke can increase the occurrence of both sides.

Baseline brain imaging signs in patients with ischaemic stroke by the presence of atrial fibrillation: the ENCHANTED trial

BACKGROUND

We aimed to assess the association of atrial fibrillation (AF) on outcomes in a post hoc analysis of the ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study) and how this association is modified by baseline imaging features.

METHODS

Inverse probability of treatment weight was used to remove baseline imbalances between those with and without AF. The primary outcome was the modified Rankin Scale (mRS) scores at 90 days. Secondary outcomes were symptomatic intracerebral haemorrhage (sICH), early neurological deterioration or death within 24 h, and death at 90 days. The logistic regression model was used to determine the associations.

RESULTS

Of the 3285 patients included in this analysis, 636 (19%) had AF at baseline. Compared with non-AF, AF was not significantly associated with an unfavourable shift of mRS (odds ratio 1.09; 95% confidence interval, 0.96-1.24), but with sICH (2.82; 1.78-4.48; IST-3 criteria), early neurological deterioration or death within 24 h (1.31; 1.01-1.70), and death (1.42; 1.12-1.79). Among patients with acute ischaemic signs (presence, extent, swelling and attenuation of acute lesions), AF was associated with the increased risk of all the poor outcomes (all P < 0.04 for interaction).

CONCLUSIONS

We found AF increased risk of sICH, early neurological deterioration or death and death, but not unfavourable functional recovery at day 90 after thrombolysis in patients with AIS. The presence of acute ischaemic brain imaging signs at stroke presentation could be used to improve risk stratification in the presence of AF.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov (NCT01422616).

Roles of Bilirubin in Hemorrhagic Transformation of Different Types and Severity

BACKGROUND

Hemorrhagic transformation (HT) is a severe complication in patients with acute ischemic stroke (AIS). This study was performed to explore and validate the relation between bilirubin levels and spontaneous HT (sHT) and HT after mechanical thrombectomy (tHT).

METHODS

The study population consisted of 408 consecutive AIS patients with HT and age- and sex-matched patients without HT. All patients were divided into quartiles according to total bilirubin (TBIL) level. HT was classified as hemorrhagic infarction (HI) and parenchymal hematoma (PH) based on radiographic data.

RESULTS

In this study, the baseline TBIL levels were significantly higher in the HT than non-HT patients in both cohorts (p < 0.001). Furthermore, the severity of HT increased with increasing TBIL levels (p < 0.001) in sHT and tHT cohorts. The highest quartile of TBIL was associated with HT in sHT and tHT cohorts (sHT cohort: OR = 3.924 (2.051-7.505), p < 0.001; tHT cohort: OR = 3.557 (1.662-7.611), p = 0.006).

CONCLUSIONS

Our results suggest that an increased TBIL is associated with a high risk of patients with sHT and tHT, and that TBIL is more suitable as a predictor for sHT than tHT. These findings may help to identify patients susceptible to different types and severity of HT.

Endovascular treatment for ischemic stroke patients with and without atrial fibrillation, and the effects of adjunctive pharmacotherapy: a narrative review

INTRODUCTION

Endovascular thrombectomy (EVT) is associated with good clinical outcomes in patients with ischemic stroke, but the impact of EVT on clinical outcomes in patients with ischemic stroke with and without atrial fibrillation (AF), and the effect of adjunctive pharmacological therapies with EVT, remains unclear.

AREAS COVERED

The goal of this narrative review is to provide an overview of studies which have examined: 1) associations between EVT and outcomes for patients following ischemic stroke, 2) associations between EVT and outcomes for patients following ischemic stroke with and without AF , including function, reperfusion, hemorrhage, and mortality, 3) the effect of adjunctive pharmacological therapies peri- and post-thrombectomy, and 4) integration of prehospital care on endovascular treatment outcomes.

EXPERT OPINION

There is little evidence from randomized controlled trials on the effect of AF on stroke outcomes following EVT and the safety and efficacy of AF treatment in the peri-EVT such as tirofiban or Intravenous thrombolysis with Non-vitamin K Antagonist Oral Anticoagulant. The available evidence from observational studies on AF and EVT outcomes is inconsistent, but factors such as procedural EVT devices, the center volume, clinician experience, stroke recognition, and inclusion criteria of studies have all been associated with poorer clinical outcomes. Enhancing the clinical network among prehospital and hospitals will facilitate direct transfer to EVT centers, reducing stroke onset to EVT time and optimizing stroke outcomes.

Patient characteristics associated with delayed neurological improvement following acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Delayed neurological improvement (DNI) is a phenomenon that involves patient improvement in the absence of early neurological change following treatment for acute ischemic stroke. The patient characteristics associated with this condition are largely unexplored.

METHODS

Following the PRISMA guidelines, a systematic review of the English language literature was conducted using PubMed, Embase, Web of science, and Scopus. We calculated pooled odds ratios (ORs), mean differences (MDs), and their corresponding 95% confidence intervals (CIs) to test the association between patient characteristics and achievement of DNI.

RESULTS

Seven studies, with 3266 patients, were included in our analysis. All studies reported a different definition of DNI, with five studies focusing on rates of good functional outcome at 90 days post-treatment in the absence of early neurological improvement. Use of intravenous thrombolytics was associated with increased rates of DNI (OR 1.96, 95% CI 1.28 to 3.00; p = 0.002). Atrial fibrillation was associated with decreased rates of DNI (OR 0.69, 95% CI 0.57 to 0.82; p < 0.001), as was hypertension (OR 0.66, 95% CI 0.53 to 0.83, p < 0.001), and diabetes mellitus (OR 0.71, 95% CI 0.56 to 0.90; p = 0.005). On average, patients who achieved DNI were 6.30 years younger than their non-DNI counterparts (MD -6.30, 95% CI -9.19 to -3.41; p < 0.001). There were modest associations between male sex and DNI (OR 1.36, 95% CI 1.01 to 1.74, p = 0.042), and smoking and DNI (OR 1.28, 95% CI 1.03 to 1.59, p = 0.027).

CONCLUSIONS

DNI is a phenomenon that is not presently well understood. Lack of uniformity among definitions of DNI hinders efforts to explore DNI and the factors associated with its occurrence. Future studies should work to establish a consensus definition of DNI to determine its causes and significance more accurately.

Successful Mechanical Thrombectomy of Bilateral Middle Cerebral Artery Occlusions Following Apixaban Discontinuation

Optimal anticoagulation management in patients with atrial fibrillation (AF) during acute ischemic stroke is complex and often poses a significant clinical challenge. An 82-year-old man with AF presented with left-sided hemiparesis and hypoesthesia due to occlusion of the right middle cerebral artery (MCA) after discontinuing apixaban for 5 days. Successful mechanical thrombectomy (MT) achieved thrombolysis in cerebral infarction (TICI) score of 2C. Anticoagulation was postponed due to a small risk of hemorrhagic conversion. However, the patient developed a rare bilateral M1 segment MCA occlusions on the fifth day with a National Institute of Health Stroke Scale (NIHSS) score of 23, leading to an emergent thrombectomy, resulting in TICI 3 and TICI 2C recanalization in left and right MCAs, respectively. The patient required admission to the intensive care unit and was eventually discharged to an inpatient rehabilitation facility with only residual left hemiparesis and moderate dysarthria. This case underscores the delicate balance between the risk of recurrent ischemic stroke and the potential for hemorrhagic conversion when treating anticoagulation in the acute setting. Close monitoring and an individualized approach are necessary for the treatment of patients with AF who have suffered an acute stroke, especially when anticoagulation must be stopped. We encourage future guidelines to incorporate both imaging and clinical data when determining the continuation of anticoagulation in patients with a recent ischemic stroke. This case also depicts the effectiveness of neuroendovascular interventions such as MT to effectively manage rare simultaneous large multi-vessel occlusions with good outcomes.

NT-proBNP Levels and Collateral Circulation Status in Patients with Acute Ischemic Stroke

Methods

In this study, 326 hospitalized patients with acute anterior circulation ischemic stroke (AACIS) were included. A comparison of the clinical characteristics of those with and without AF was conducted. The Spearman rank correlation was used for the correlation analysis of plasma NT-proBNP level, regional leptomeningeal collateral (rLMC) score, and computed tomography perfusion (CTP) status in the AF and non-AF groups. An analysis of multivariate linear regression was used to determine how plasma NT-proBNP level, rLMC score, and CTP status influenced the score on the NIHSS.

Results

There was a greater plasma NT-proBNP level in the AF group compared with the non-AF group, an increased CTP volume (including CTP ischemic volume, CTP infarct core volume, and CTP ischemic penumbra volume (P = 0.002)), higher NIHSS score on admission, and lower rLMC score (P < 0.001 for the remaining parameters). A negative correlation exists between plasma NT-proBNP level and rLMC score (r = -0.156, P = 0.022), but a positive correlation exists between plasma NT-proBNP level and both CTP ischemic volume and CTP infarct core volume (r = 0.148, P = 0.003) in the AF group, but not in the non-AF group. Multivariate linear regression analysis demonstrated that NT-proBNP, CTP ischemic penumbra volume, and rLMC score were associated with NIHSS score, and NT-proBNP was positively associated with NIHSS scores (95% confidence interval (CI), 0.000-0.002; P = 0.004) in the AF group, whatever in the unadjusted model or adjusted models, but not in the nonlarge artery atherosclerosis (LAA) group.

Conclusion

In AACIS patients with AF, NT-proBNP level negatively correlated with collateral status, positively with CTP ischemic volume, and positively with NIHSS score.

Determinants of 1-Year Unfavorable Outcomes of Intravenous Alteplase Thrombolysis for Acute Ischemic Stroke

OBJECTIVE

Intravenous thrombolytic therapy has become the standard of treatment for eligible patients with ischemic stroke. However, outcomes after receiving intravenous thrombolytic therapy vary widely. This study aims to investigate determinants of 1-year clinical outcomes of intravenous thrombolytic therapy for patients with acute ischemic stroke.

METHODS

In a prospective, observational study, patients with acute ischemic stroke treated with intravenous thrombolysis were consecutively included, and clinical information and laboratory data were collected. The patients were followed up for 12 months after onset, and the 1-year clinical outcome was evaluated using modified Rankin Scale scores. A score ≥ 3 was defined as unfavorable functional outcome. Univariate and multivariate logistic regressions were used to assess the determinants of the 1-year clinical outcomes of intravenous thrombolysis for acute ischemic stroke.

RESULTS

A total of 222 patients with intravenous thrombolysis were enrolled, and we identified 58 patients (26.1%) had unfavorable functional outcomes. Multivariate logistic regression analysis revealed that mean platelet volume-to-lymphocyte ratio (MPVLR) (odds ratio [OR] = 1.114, 95% confidence interval [CI]: 1.024-1.211, P = .012), atrial fibrillation (OR =  2.553, 95% CI: 1.086-6.002, P = .032), symptomatic stenosis occlusion (OR =  2.547, 95% CI: 1.269-5.110, P = .009), and baseline National Institutes of Health Stroke Scale (NIHSS) score (OR = 1.141, 95% CI: 1.074-1.212, P < .001) were independent predictors of unfavorable functional outcomes at 1 year.

CONCLUSIONS

In patients receiving intravenous thrombolysis, we found that MPVLR, atrial fibrillation, symptomatic stenosis occlusion, and baseline NIHSS score were significant predictors of unfavorable functional outcomes at 1 year.

Safety of Recanalization Therapy in Acute Ischemic Stroke Patients on Direct Oral Anticoagulant Therapy: An Updated Systematic Review and Meta-Analysis

This review provides an updated assessment of the safety of recanalization therapy for Acute Ischemic Stroke (AIS) patients receiving direct oral anticoagulants (DOAC) therapy. We checked the literature for published observational from 1st January 1950 to 31st March 2021. The rate of symptomatic intracerebral hemorrhage (sICH), arterial recanalization rate, good functional recovery, and mortality at 3 months were investigated, and data were expressed as Risk ratio (RR) with a 95% confidence interval (CI). Publication bias, sensitivity analysis, and meta-regression analyses were conducted utilizing STATA software. 17 articles [14 for endovascular therapy (EVT) and 3 intravenous thrombolysis for (IVT)] were finally included in the review. AIS patients with DOAC therapy showed a decreased rate of sICH (RR = 0.85, 95% CI = 0.72 to 1.00, P = 0.04), and lower probability of good functional recovery at three months (RR = 0.79, 95% CI = 0.73 to 0.85, P < 0.001) than patients without anticoagulation therapy post EVT. However, no significant differences in sICH rates in AIS patients with DOAC therapy after IVT (RR = 0.87, 95% CI = 0.48 to 1.58, P = 0.64) were observed. AIS patients not prescribed DOAC after EVT had a higher mortality risk (RR = 1.29, 95% CI = 1.15-1.44, P < 0.001). Patients with AIS on DOAC therapy were found to have a lower incidence of sICH following EVT. However, no evidence of an increased bleeding risk in patients previously treated with DOAC after IVT was observed. Therefore, more detailed studies with biological data to monitor compliance and details on the size and etiology/severity of the incident ischemic lesion is needed.

Improving detection and management of atrial fibrillation after ischaemic stroke in Glasgow (IMPROVE-AF): A quality improvement project

Introduction:

The use of cardiac monitoring to detect atrial fibrillation (AF) is routine after ischaemic stroke but is often delayed leaving patients at risk from undetected AF. We sought to improve the detection of AF by delivering early prolonged ‘in-house’ cardiac monitoring.

Patients and methods:

We collected 3-months of data of people with stroke/transient ischaemic attack (TIA), but without AF, who underwent cardiac monitoring (Phase 1, pre-quality improvement project (QIP)). We then implemented an ‘in-house’ 7-day cardiac monitoring service for 12 months (Phase 2, during QIP).

Results:

We included 244 people in Phase 1 and 172 in Phase 2. In Phase 1, 232 (95%) people completed cardiac monitoring. Of these, new AF was detected in 10 (4%). Median time from stroke/TIA onset to availability of the monitoring report in Phase 1 was 50 (interquartile range (IQR): 24–123) days. In Phase 2, 166 (97%) of people completed 7-day cardiac monitoring, with new AF detected in 17 (10%). Median time from onset to availability of the report in Phase 2 was 12 (IQR: 9–15) days. In people with AF detected, ‘in-house’ monitoring reduced the time of stroke/TIA onset to anticoagulant commencement from 41 (Phase 1) to 14 (Phase 2) days.

Conclusions:

The QIP has improved AF detection, reduced delays associated with conventional cardiac monitoring and prompted early initiation of oral anticoagulation.

High Prevalence of Atrial Fibrillation in a Lithuanian Stroke Patient Cohort

Background and Objectives: Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with a five-fold increased risk for acute ischemic stroke (AIS). We aimed to estimate the prevalence of AF in a Lithuanian cohort of stroke patients, and its impact on patients regarding case fatality, functional outcome, and health-related quality of life (HRQoL) at 90 days. Materials and Methods: A single-center prospective study was carried out for four non-consecutive months between December 2018 and July 2019 in one of the two comprehensive stroke centers in Eastern Lithuania. A telephone-based follow-up was conveyed at 90 days using the modified Rankin Scale (mRS) and EuroQoL five-dimensional three-level descriptive system (EQ-5D-3L) with a self-rated visual analog scale (EQ-VAS). One-year case fatality was investigated. Results: We included 238 AIS patients with a mean age of 71.4 ± 11.9 years of whom 45.0% were female. A striking 97 (40.8%) AIS patients had a concomitant AF, in 68 (70.1%) of whom the AF was pre-existing. The AIS patients with AF were at a significantly higher risk for a large vessel occlusion (LVO; odds ratio 2.72 [95% CI 1.38−5.49], p = 0.004), and had a more severe neurological impairment at presentation (median NIHSS score (interquartile range): 9 (6−16) vs. 6 (3−9), p < 0.001). The LVO status was only detected in those who had received computed tomography angiography. Fifty-five (80.9%) patients with pre-existing AF received insufficient anticoagulation at stroke onset. All patients received a 12-lead ECG, however, in-hospital 24-h Holter monitoring was only performed in 3.4% of AIS patients without pre-existing AF. Although multivariate analyses found no statistically significant difference in one-year stroke patient survival and favorable functional status (mRS 0−2) at 90 days, when adjusted for age, gender, reperfusion treatment, baseline functional status, and baseline NIHSS, stroke patients with AF had a significantly poorer self-perceived HRQoL, indicated by a lower EQ-VAS score (regression coefficient ± standard error: β = −11.776 ± 4.850, p = 0.017). Conclusions: In our single-center prospective observational study in Lithuania, we found that 40.8% of AIS patients had a concomitant AF, were at a higher risk for an LVO, and had a significantly poorer self-perceived HRQoL at 90 days. Despite the high AF prevalence, diagnostic tools for subclinical AF were greatly underutilized.

Analysis of Factors Associated with Hemorrhagic Transformation in Acute Cerebellar Infarction

OBJECTIVES

Hemorrhagic transformation (HT) is a frequent and severe complication of ischemic stroke. This study aimed to evaluate the factors associated with the occurrence of HT in patients with acute cerebellar infarction.

MATERIALS AND METHODS

A total of 190 patients, 141 male (74.2%) and 49 female (25.8%) with mean age 61.84 ± 12.16 years, who were admitted within 72 h of acute cerebellar infarction onset from January 2017 to March 2021 were retrospectively recruited. The multivariate logistic regression analysis was used to evaluate the independent influent factors for HT and receiver-operating characteristic (ROC) curve was applied to calculate the predictive value of those factors for HT in patients with acute cerebellar infarction.

RESULTS

37 out of 190 recruited patients (19.47%) had HT within 14 days after acute cerebellar infarction onset. The incidence rates of HT occurring within 3 days, 3-7 days and 7-14 days were 13.5%, 40.5% and 45.9%, respectively. Results of the multivariable logistic regression analysis indicated that atrial fibrillation (AF) (OR 6.196, 95% CI 1.357-28.302, P = 0.019), infarct diameter (OR 5.813, 95% CI 2.932-11.526, P < 0.001), white matter hyperintensity (WMH) (OR 2.44, 95% CI 1.134-5.252, P = 0.023) were independent risk factors for HT in acute cerebellar infarction, while lymphocyte count (OR 0.319, 95% CI 0.142-0.716, P = 0.006) showed an independently protective effect.

CONCLUSIONS

Infarct diameter, AF and WMH are independent risk factors for HT in patients with acute cerebellar infarction, while the lymphocyte count is a protective factor.

Higher Mortality Associated With New-Onset Atrial Fibrillation in Cancer Patients: A Systematic Review and Meta-Analysis

Aim

This research was conducted to evaluate the mortality outcome of cancer patients with new-onset atrial fibrillation. We also aimed to assess if there was any confounding relation between the mortality of these patients and surgical intervention.

Materials and Methods

A systemic search was conducted from electronic databases (PubMed/Medline, Cochrane Library, and Google Scholar) from inception to 7 February 2022. All statistical analyses were conducted in Review Manager 5.4.1. Studies meeting inclusion criteria were selected. Only those studies that involved cancer patients without pre-existing atrial fibrillation were selected, and mortality rate was compared between the patients who developed atrial fibrillation and those who did not. A random-effect model was used when heterogeneity was seen to pool the studies, and the result was reported in the odds ratio (OR) and the corresponding 95% confidence interval (CI).

Results

Eighteen studies were selected for meta-analysis. Statistical analysis showed that the cancer patients who subsequently developed atrial fibrillation had a significantly higher mortality rate as compared to those who did not (OR = 1.90 [1.65, 2.19]; p &lt; 0.00001; I2 = 100%). We also separately analyzed the mortality risk in the surgery group and the non-surgery group. Statistical analysis showed that there was significantly higher mortality rate associated with new-onset atrial fibrillation in cancer patients in the surgery group (OR= 3.68 [2.29, 5.94]; p &lt; 0.00001; I2 = 61%) as well as in the non-surgery group (OR = 1.64 [1.39, 1.93]; p &lt; 0.00001; I2 = 100%).

Conclusion

Cancer patients, who subsequently developed atrial fibrillation, had a higher mortality rate as compared to those cancer patients who did not develop atrial fibrillation. A higher mortality rate was seen in both surgical and non-surgical subgroups. This implies that extra care and specific measures must be taken in the management of cancer patients with new-onset atrial fibrillation.

Neuroprotective Mechanisms of Glucagon-Like Peptide-1-Based Therapies in Ischemic Stroke: An Update Based on Preclinical Research

The public and social health burdens of ischemic stroke have been increasing worldwide. Hyperglycemia leads to a greater risk of stroke. This increased risk is commonly seen among patients with diabetes and is in connection with worsened clinical conditions and higher mortality in patients with acute ischemic stroke (AIS). Therapy for stroke focuses mainly on restoring cerebral blood flow (CBF) and ameliorating neurological impairment caused by stroke. Although choices of stroke treatment remain limited, much advance have been achieved in assisting patients in recovering from ischemic stroke, along with progress of recanalization therapy through pharmacological and mechanical thrombolysis. However, it is still necessary to develop neuroprotective therapies for AIS to protect the brain against injury before and during reperfusion, prolong the time window for intervention, and consequently improve neurological prognosis. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are broadly regarded as effective drugs in the treatment of type 2 diabetes mellitus (T2DM). Preclinical data on GLP-1 and GLP-1 RAs have displayed an impressive neuroprotective efficacy in stroke, Parkinson's disease (PD), Alzheimer's disease (AD), Amyotrophic lateral sclerosis (ALS), and other neurodegenerative diseases. Based on the preclinical studies in the past decade, we review recent progress in the biological roles of GLP-1 and GLP-1 RAs in ischemic stroke. Emphasis will be placed on their neuroprotective effects in experimental models of cerebral ischemia stroke at cellular and molecular levels.

Hemorrhagic Transformation in Acute Ischemic Stroke: A Quantitative Systematic Review

The prevalence and risk factors of hemorrhagic transformation (HT) after acute ischemic stroke HT have not been adequately delineated. We performed a systematic review and meta-analysis to identify English-language prospective observational MEDLINE and EMBASE-listed reports of acute ischemic stroke with HT published from 1985–2017. Studies that used the ECASS-2 definitions of hemorrhagic transformation subtypes, hemorrhagic infarction (HI), and parenchymal hematoma (PH) were included. Patients treated with intravenous thrombolysis with tissue plasminogen activator (IV-tPA) were compared with those who did not receive thrombolysis. A total of 65 studies with 17,259 patients met inclusion criteria. Overall, HT prevalence was 27%; 32% in patients receiving IV-tPA vs. 20% in those without. Overall PH prevalence was 9%; 12% in IV-tPA treated patients vs. 5% in those without. HT was associated with a history of atrial fibrillation (OR 2.94) and use of anticoagulants (OR 2.47). HT patients had higher NIHSS (Hedge’s-G 0.96) and larger infarct volume (diffusion-weighted MRI, Hedge’s-G 0.8). In IV-tPA treated patients, PH correlated with antiplatelet (OR 3) and statin treatment (OR 4). HT (OR 3) and PH (OR 8) were associated with a poor outcome at 90-day (mRS 5–6). Hemorrhagic transformation is a frequent complication of acute ischemic stroke and is associated with poor outcome. Recognition of risk factors for HT and PH may reduce their incidence and severity.

Use of Prolonged Cardiac Rhythm Monitoring to Identify Atrial Fibrillation After Cryptogenic Stroke

PURPOSE OF REVIEW

Prolonged cardiac monitoring (PCM) improves detection of atrial fibrillation (AF) after cryptogenic stroke. We summarize current research supporting the use of PCM as part of the cryptogenic stroke evaluation, while highlighting areas that require more investigation.

RECENT FINDINGS

Despite increased AF detection with longer durations of PCM, more definitive research is needed to demonstrate how PCM improves clinical outcomes. The optimal type, timing, and length of cardiac monitoring after cryptogenic stoke remains unknown. Clinical calculators will be important to risk stratify which cryptogenic stroke patients are most likely to benefit from PCM. Currently, AF detection after cryptogenic stroke should prompt consideration of anticoagulation, but it is unclear if all durations and timing of AF after stroke should be treated the same. PCM remains an important part of the cryptogenic stroke work up, and detection of AF allows for anticoagulation initiation. Additional research is needed to further refine our application of PCM to cryptogenic stroke.

Comparison of Different Dosages of Alteplase in Atrial Fibrillation-Related Acute Ischemic Stroke After Intravenous Thrombolysis: A Nationwide, Multicenter, Prospective Cohort Study in Taiwan

Background

Insufficient evidence is available for patients with acute ischemic stroke with atrial fibrillation (AF) to determine the efficacy and safety of different dosages of intravenous thrombolysis treatment. This study examined clinical outcomes in Chinese patients with stroke with and without AF after intravenous thrombolysis treatment with different intravenous thrombolysis doses.

Methods and Results

This multicenter, prospective cohort study recruited 2351 patients with acute ischemic stroke (1371 with AF and 980 without AF) treated with intravenous thrombolysis using alteplase. The Totaled Health Risks in Vascular Events score is a validated risk‐scoring tool used for assessing patients with acute ischemic stroke with and without AF. We evaluated favorable functional outcome at day 90 and symptomatic intracranial hemorrhage within 24 to 36 hours and outcomes of the patients receiving different doses of alteplase. Compared with the non‐AF group, the AF group exhibited a 2‐ to 3‐fold increased risk of symptomatic intracranial hemorrhage according to the National Institute of Neurological Disorders and Stroke standard (relative risk [RR], 2.10 [95% CI, 1.35–3.26]). Favorable functional outcome at 90 days and symptomatic intracranial hemorrhage rates according to the European Cooperative Acute Stroke Study II and the Safe Implementation of Thrombolysis in Stroke‐Monitoring Study standards did not significantly differ between the AF and non‐AF groups. In addition, the low‐dose alteplase subgroup exhibited an increased risk of symptomatic intracranial hemorrhage according to the National Institute of Neurological Disorders and Stroke standard (RR, 2.84 [95% CI, 1.63–4.96]). A validation study confirmed these findings after adjustment for scores determined using different stroke risk‐scoring tools.

Conclusions

Different alteplase dosages did not affect functional status at 90 days in the AF and non‐AF groups. Thus, the adoption of low‐dose alteplase simply because of AF is not recommended.

Mechanical Thrombectomy Up to 24 Hours in Large Vessel Occlusions and Infarct Velocity Assessment

Background

We retrospectively compared early‐ (<6 hours) versus late‐ (6–24 hours) presenting patients using perfusion‐weighted imaging selection and evaluated clinical/radiographic outcomes.

Methods and Results

Large vessel occlusion patients treated with mechanical thrombectomy from August 2017 to July 2020 within 24 hours of onset were retrieved from a single‐center database. Perfusion‐weighted imaging was analyzed by automated software and final infarct volume was measured semi‐automatically within 14 days. The primary end point was good outcome (modified Rankin Scale 0–2 at 90 days). Secondary end points were excellent outcome (modified Rankin Scale 0–1 at 90 days), symptomatic intracranial hemorrhage, and death. Clinical characteristics/radiological values including hypoperfusion volume and infarct growth velocity (baseline volume/onset‐to‐image time) were compared between the groups. Of 1294 patients, 118 patients were included. The median age was 74 years, baseline National Institutes of Health Stroke Scale score was 14, and core volume was 13 mL. The late‐presenting group had more female patients (67% versus 31%, respectively; P=0.001). No statistically significant differences were seen in good outcome (42% versus 53%, respectively; P=0.30), excellent outcome (26% versus 32%, respectively; P=0.51), symptomatic intracranial hemorrhage (6.5% versus 4.6%, respectively; P=0.74), and death (3.2% versus 5.7%, respectively; P=0.58) between the groups. The late‐presenting group had more atherothrombotic cerebral infarction (19% versus 6%, respectively; P=0.03), smaller hypoperfusion volume (median: 77 versus 133 mL, respectively; P=0.04), and slower infarct growth velocity (median: 0.6 versus 5.1 mL/h, respectively; P=0.03).

Conclusions

Patients with early‐ and late‐time windows treated with mechanical thrombectomy by automated perfusion‐weighted imaging selection have similar outcomes, comparable with those in randomized trials, but different in infarct growth velocities.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02251665.

Long-Term Follow-up of Enhanced Holter-Electrocardiography Monitoring in Acute Ischemic Stroke

Background and Purpose

Prolonged electrocardiography (ECG)-monitoring in stroke patients improves the detection of paroxysmal atrial fibrillation (pAF). However, most randomized studies only had short follow-up. We aimed to provide 3-year follow-up data for AF detection and stroke recurrence risk.

Methods

We randomized 402 patients aged ≥60 years with acute ischemic strokes without AF to either enhanced and prolonged monitoring (EPM; 3×10-day Holter-ECG-monitoring) or standard-of-care (≥24 hours ECG-monitoring). The endpoint of the current analysis was AF within 36 months analyzed by intention to treat. Long-term follow-up was performed for 36 months.

Results

Two hundred and seventy-four patients (80%) participated in the extended follow-up (median duration of follow-up was 36 months [interquartile range, 12 to 36]). During the first 6 months, more AF was documented in the EPM arm compared to the control arm (13.5% vs. 5.1%; 95% confidence interval, 2.9% to 14.4%; P=0.004). During months 6 to 36, AF was less detected in the EPM intervention arm than in the control arm (2.0% vs. 7.3%; 95% confidence interval, 0.7% to 9.9%; P=0.028). Overall, the detection rate of AF within 36 months was numerically higher within the EPM group (15.0% vs. 11.1%, P=0.30). Numerically less patients in the EPM arm had recurrent ischemic strokes (5.5% vs. 9.1%, P=0.18), transient ischemic attacks (3.0% vs. 4.5%, P=0.44) or died (4.5% vs. 6.6%, P=0.37).

Conclusions

Enhanced and prolonged ECG monitoring increased AF detection during the first six months, but there was significantly more clinical AF during months 6 to 36 observed in the usual-care arm. This suggests that EPM leads to an earlier detection of clinically relevant AF.

A Review of Risk Factors and Predictors for Hemorrhagic Transformation in Patients with Acute Ischemic Stroke

Acute ischemic strokes (AIS) and hemorrhagic strokes lead to disabling neuropsychiatric and cognitive deficits. A serious and fatal complication of AIS is the occurrence of hemorrhagic transformation (HT). HT is cerebral bleeding that occurs after an ischemic event in the infarcted areas. This review summarises how specific risk factors such as demographic factors like age, gender, and race/ethnicity, comorbidities including essential hypertension, atrial fibrillation, diabetes mellitus, congestive heart failure, and ischemic heart disease along with predictors like higher NIHSS score, larger infarction size, cardioembolic strokes, systolic blood pressure/pulse pressure variability, higher plasma glucose levels, and higher body temperature during ischemic event, lower low-density lipoprotein and total cholesterol, early ischemic changes on imaging modalities, and some rare causes make an individual more susceptible to developing HT. We also discuss few other risk factors such as the role of blood-brain barrier, increased arterial stiffness, and globulin levels in patients postreperfusion using thrombolysis and mechanical thrombectomy. In addition, we discuss the implications of dual antiplatelet therapy and the length of treatment in reference to the incidence of developing HT. Current research into inflammatory mediators and biomarkers such as Cyclooxygenase-2, matrix metalloproteinases, and soluble ST2 and their potential role as treatment options for HT is also briefly discussed. Finally, this review calls for more research into use of dual antiplatelet and the timing of antiplatelet and anticoagulant use in reference to hemorrhagic transformation.

Quality of life after ischaemic stroke—accent on patients with thrombolytic therapy

Background

Intravenous thrombolysis is a widely approved treatment method for acute ischemic stroke (AIS). Nevertheless, there is a growing interest in its impact on functional outcomes and Health-related Quality of life (HR-QoL). We aimed to evaluate and compare the HR-QoL in patients receiving intravenous thrombolysis (IVT) and in those without thrombolytic therapy during the first 3-month post-stroke in a defined Bulgarian population.

Results

Patients treated with IVT have simillar functional outcomes and HR-QoL on the third month as the group with conservative treatment, besides their higher NIHSS on admission. Patients with IVT had better self-assessed recovery after the AIS. The higher NIHSS and mRS scores and the lower HR-QoL on discharge are reliable predictors for a poor functional outcome on the third month. A door-to-needle of 60 min or less, and the absence of pathological neuroimaging findings 24-h post IVT predict more beneficial HR-QoL outcome.

Conclusion

There were no significant differences in HR-QoL and functional outcomes between the groups. Nevertheless, IVT is a treatment option with great importance for improving the clinical outcomes after ischemic stroke, which should be performed in well selected patients.

Predictors and Prognosis of Symptomatic Intracranial Hemorrhage in Acute Ischemic Stroke Patients Without Thrombolysis: Analysis of Data From the Chinese Acute Ischemic Stroke Treatment Outcome Registry

Background and Purpose: There is limited information on symptomatic intracranial hemorrhage (sICH) in stroke patients without thrombolysis. This study aimed to evaluate the risk factors of sICH and the association between sICH and the prognosis at 3 and 12 months in acute ischemic stroke patients without thrombolysis.

Methods: Data originated from the Chinese Acute Ischemic Stroke Treatment Outcome Registry. Univariate analysis and multivariate logistic regression were used to screen the risk factors of sICH. Multivariable logistic regression models were used to assess the association of sICH with poor outcome and all-cause mortality.

Results: Totally, 9,484 patients were included, of which 69 (0.73%) had sICH. Atrial fibrillation (odds ratio [OR], 3.682; 95% confidence interval [CI], 1.945–6.971; p < 0.001), history of tumors (OR, 2.956; 95% CI, 1.115–7.593; p = 0.024), and the National Institutes of Health Stroke Scale (NIHSS) score on admission ([6–15: OR, 2.344; 95% CI, 1.365–4.024; p = 0.002] [>15: OR, 4.731; 95% CI, 1.648–13.583; p = 0.004]) were independently associated with sICH. After adjustment of the confounders, patients with sICH had a higher risk of poor outcome (OR, 1.983; 95% CI, 1.117–3.521; p = 0.018) at 3 months and that of all-cause mortality at 3 (OR, 6.135; 95% CI, 2.328–16.169; p < 0.001) and 12 months (OR, 3.720; 95% CI, 1.513–9.148; p = 0.004).

Conclusion: sICH occurred in 0.73% of acute ischemic stroke patients without thrombolysis and was associated with a worse prognosis at 3 and 12 months. Atrial fibrillation, history of tumors, and NIHSS score at admission were independent risk factors of sICH.

Comparing the Prognostic Impact of Age and Baseline National Institutes of Health Stroke Scale in Acute Stroke due to Large Vessel Occlusion

[Figure: see text].

Risk Factors of Hypoperfusion on MRI of Ischemic Stroke Patients Within 7 Days of Onset

Objective: Hypoperfusion is an important factor determining the prognosis of ischemic stroke patients. The present study aimed to investigate possible predictors of hypoperfusion on MRI of ischemic stroke patients within 7 days of stroke onset.

Methods: Ischemic stroke patients, admitted to the comprehensive Stroke Center of Shanghai Fourth People's Hospital affiliated to Tongji University within 7 days of onset between January 2016 and June 2017, were recruited to the present study. Magnetic resonance imaging (MRI), including both diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI), was performed within 7 days of the symptom onset. Time to maximum of the residue function (T_max) maps were automatically evaluated using the RAPID software. The volume of hypoperfusion was measured outside the infarct area based on ADC < 620 × 10⁻⁶ mm²/s. The 90 d mRS score was assessed through either clinic visits or telephone calls. Multivariate step-wise analysis was used to assess the correlation between MR findings and clinical variables, including the demographic information, cardio-metabolic characteristics, and functional outcomes.

Results: Among 635 patients admitted due to acute ischemic stroke within 7 days of onset, 241 met the inclusion criteria. Hypoperfusion volume of 38 ml was the best cut-off value for predicting poor prognosis of patients with cerebral infarction (90 d-mRS score ≥ 2). The incidences of MR perfusion T_max > 4–6 s maps with a volume of 0–38 mL or >38 mL were 51.9% (125/241) and 48.1% (116/241), respectively. Prior stroke and vascular stenosis (≥70%) were associated with MR hypoperfusion. Multivariate step-wise analysis showed that prior stroke and vascular stenosis (≥70%) were risk factors of T_max > 4–6 s maps, and the odds ratios (OR) were 3.418 (adjusted OR 95% CI: 1.537–7.600), and 2.265 (adjusted OR, 95% CI: 1.199–4.278), respectively.

Conclusion: Our results suggest that prior stroke and vascular stenosis (≥70%) are strong predictors of hypoperfusion in patients with acute ischemic stroke within 7 days of stroke onset.

Ischemic Stroke With Atrial Fibrillation: Characteristics and Time Trends 2006 to 2017 in the Dijon Stroke Registry

[Figure: see text].

Efficacy and safety of thrombolysis for acute ischemic stroke with atrial fibrillation: a meta-analysis

Background

The efficacy and safety of intravenous thrombolysis (IVT) for acute ischemic stroke with atrial fibrillation (AF) is still controversial.

Methods

We conducted a meta-analysis of all relevant studies, retrieved through systematic search of PubMed, Embase, and Cochrane databases up to December 31, 2019. Modified Rankin Scale (mRS) scores of 0–1 at 90 days, mRS of 0–2 at 90 days, overall mortality, and incidence of symptomatic intracranial hemorrhage (sICH) were collected as outcome measures. Fixed- and random-effects meta-analytical models were applied, and between-study heterogeneity was assessed.

Results

A total of 8509 patients were enrolled in 18 studies. A comparison of IVT treatment in AF versus non-AF patients showed that AF was associated with a significantly lower proportion of patients with mRS of 0–1 (24.1% vs. 34.5%; OR 0.59; 95% CI 0.43–0.81; P < 0.001), mRS of 0–2 (33.6% vs. 47.8%; OR 0.55; 95% CI 0.43–0.70; P < 0.001), as well as significantly higher mortality (19.4% vs. 11.5%; OR 2.05; 95% CI 1.79–2.36; P < 0.001) and higher incidence of sICH (6.4% vs. 4.1%; OR 1.60; 95% CI 1.27–2.01; P < 0.001). A comparison of AF patients who were subjected or not to IVT showed that thrombolysis carried a higher risk of sICH (5.7% vs. 1.6%; OR 3.44; 95% CI 2.04–5.82; P < 0.001) and was not associated with a better prognosis. Subgroup analysis in prospective studies also suggested a poorer functional prognosis and higher mortality in AF patients treated with IVT compared with those who did not receive IVT. Some heterogeneity was present in this meta-analysis.

Conclusions

Acute IS patients with AF had worse outcomes than those without AF after thrombolytic therapy, and had a higher incidence of sICH after thrombolysis than those without thrombolysis. Thrombolysis in ischemic stroke patients with AF should be carefully considered based on clinical factors such as NIHSS score, age, and the type of AF.